Decreased Circulating Visfatin Is Associated with Improved Disease Activity in Early Rheumatoid Arthritis: Data from the PERAC Cohort

Objective

To evaluate circulating visfatin and its relationship with disease activity and serum lipids in patients with early, treatment-naïve rheumatoid arthritis (RA).

Methods

Serum visfatin was measured in 40 patients with early RA before and after three months of treatment and in 30 age- and sex-matched healthy individuals. Disease activity was assessed using the Disease Activity Score for 28 joints (DAS28) at baseline and at three and 12 months. Multivariate linear regression analysis was performed to evaluate whether improved disease activity is related to serum visfatin or a change in visfatin level.

Results

Serum visfatin was significantly elevated in early RA patients compared to healthy controls (1.92±1.17 vs. 1.36±0.93 ng/ml; p = 0.034) and significantly decreased after three months of treatment (to 0.99±0.67 ng/ml; p<0.001). Circulating visfatin and a change in visfatin level correlated with disease activity and improved disease activity over time, respectively. A decrease in visfatin after three months predicted a DAS28 improvement after 12 months. In addition, decreased serum visfatin was not associated with an improved atherogenic index but was associated with an increase in total cholesterol level.

Conclusion

A short-term decrease in circulating visfatin may represent an independent predictor of long-term disease activity improvement in patients with early RA.     

Different Risk of Tuberculosis and Efficacy of Isoniazid Prophylaxis in Rheumatoid Arthritis Patients with Biologic Therapy: A Nationwide Retrospective Cohort Study in Taiwan

Increasing evidence indicates an increased risk of tuberculosis (TB) for rheumatoid arthritis (RA) patients receiving biologic therapy, and the effectiveness of isoniazid prophylaxis (INHP) in TB prevention. We aimed to examine 1) the incidence rate (IR) and risk factors for TB among RA patients receiving different therapies; 2) INHP effectiveness for TB prevention; 3) mortality rates after TB diagnosis in patients receiving different therapies. This retrospective study was conducted using a nationwide database: 168,720 non-RA subjects and a total of 42,180 RA patients including 36,162 csDMARDs-exposed, 3,577 etanercept-exposed, 1,678 adalimumab-exposed and 763 rituximab-exposed patients. TB risk was 2.7-fold higher in RA cohort compared with non-RA group, with an adjusted hazard ratio (aHR) of 2.58. Advanced age, male, the use of corticosteroids≧5mg/day, and the presence of diabetes mellitus (DM), chronic obstructive pulmonary disease and chronic kidney disease were risk factors for developing TB. Using csDMARDs-exposed group as reference, aHR of TB was the highest with adalimumab treatment (1.52), followed by etanercept (1.16), and the lowest with rituximab (0.08). INHP could effectively reduce TB risk in biologics-exposed patients. Mortality rates after TB diagnosis were higher in RA patients, particularly the elderly and those with DM, with lower rates in adalimumab-exposed patients compared with csDMARDs-exposed patients. In conclusion, TB risk was increased in patients receiving TNF-α inhibitors, but the risk associated with rituximab therapy was relatively low. With the effectiveness of INHP shown in the prevention of biologics-associated TB, stricter implementation of INHP should be beneficial. The mortality from biologics–associated TB may be efficiently reduced through increased awareness.     

Comparing Effects of Biologic Agents in Treating Patients with Rheumatoid Arthritis: A Multiple Treatment Comparison Regression Analysis

Rheumatoid arthritis patients have been treated with disease modifying anti-rheumatic drugs (DMARDs) and the newer biologic drugs. We sought to compare and rank the biologics with respect to efficacy. We performed a literature search identifying 54 publications encompassing 9 biologics. We conducted a multiple treatment comparison regression analysis letting the number experiencing a 50% improvement on the ACR score be dependent upon dose level and disease duration for assessing the comparable relative effect between biologics and placebo or DMARD. The analysis embraced all treatment and comparator arms over all publications. Hence, all measured effects of any biologic agent contributed to the comparison of all biologic agents relative to each other either given alone or combined with DMARD. We found the drug effect to be dependent on dose level, but not on disease duration, and the impact of a high versus low dose level was the same for all drugs (higher doses indicated a higher frequency of ACR50 scores). The ranking of the drugs when given without DMARD was certolizumab (ranked highest), etanercept, tocilizumab/ abatacept and adalimumab. The ranking of the drugs when given with DMARD was certolizumab (ranked highest), tocilizumab, anakinra, rituximab, golimumab/ infliximab/ abatacept, adalimumab/ etanercept. Still, all drugs were effective. All biologic agents were effective compared to placebo, with certolizumab the most effective and adalimumab (without DMARD treatment) and adalimumab/ etanercept (combined with DMARD treatment) the least effective. The drugs were in general more effective, except for etanercept, when given together with DMARDs.     

Serological and Progression Differences of Joint Destruction in the Wrist and the Feet in Rheumatoid Arthritis - A Cross-Sectional Cohort Study

Objective

To investigate clinical and radiological differences between joint destruction in the wrist and the feet in patients with RA.

Methods

A cross-sectional clinical study was conducted in an RA cohort at a single institution. Clinical data included age, sex and duration of disease. Laboratory data included sero-positivity for anti-cyclic citrullinated peptide (CCP) antibody and RF. Radiological measurements included Larsen grades and the modified Sharp/van der Heijde method (SHS) for the hands/wrists and the feet. Statistical analyses were performed using the Kruskal—Wallis H-test, a dummy variable linear regression model and multivariate logistic regression analysis with 95% confidence interval and odds ratios.

Results

A total of 405 patients were enrolled, and 314 patients were analysed in this study. The duration of disease in the foot-dominant group was significantly less than that in the wrist-dominant group. When patients were subdivided by duration of disease, the Larsen grade of the feet was significantly higher than that of the wrist in the first quadrant subgroup, but this was reversed with increasing duration of disease. Anti-CCP status was a significant predictive factor for joint destruction in the wrist but not in the feet, while RF status was not predictive in either the wrist or the feet.

Conclusions

Joint destruction in the feet started earlier than in the wrist, but the latter progresses faster with increasing duration of disease. Anti-CCP status predicts joint destruction in the wrist better than in the feet.     

Multiparameter Phospho-Flow Analysis of Lymphocytes in Early Rheumatoid Arthritis: Implications for Diagnosis and Monitoring Drug Therapy

Background

The precise mechanisms involved in the initiation and progression of rheumatoid arthritis (RA) are not known. Early stages of RA often have non-specific symptoms, delaying diagnosis and therapy. Additionally, there are currently no established means to predict clinical responsiveness to therapy. Immune cell activation is a critical component therefore we examined the cellular activation of peripheral blood mononuclear cells (PBMCs) in the early stages of RA, in order to develop a novel diagnostic modality.

Methods and Findings

PBMCs were isolated from individuals diagnosed with early RA (ERA) (n = 38), longstanding RA (n = 10), osteoarthritis (OA) (n = 19) and from healthy individuals (n = 10). PBMCs were examined for activation of 15 signaling effectors, using phosphorylation status as a measure of activation in immunophenotyped cells, by flow cytometry (phospho-flow). CD3+CD4+, CD3+CD8+ and CD20+ cells isolated from patients with ERA, RA and OA exhibited activation of multiple phospho-epitopes. ERA patient PBMCs showed a bias towards phosphorylation-activation in the CD4+ and CD20+ compartments compared to OA PBMCs, where phospho-activation was primarily observed in CD8+ cells. The ratio of phospho (p)-AKT/p-p38 was significantly elevated in patients with ERA and may have diagnostic potential. The mean fluorescent intensity (MFI) levels for p-AKT and p-H3 in CD4+, CD8+ and CD20+ T cells correlated directly with physician global assessment scores (MDGA) and DAS (disease activity score). Stratification by medications revealed that patients receiving leflunomide, systemic steroids or anti-TNF therapy had significant reductions in phospho-specific activation compared with patients not receiving these therapies. Correlative trends between medication-associated reductions in the levels of phosphorylation of specific signaling effectors and lower disease activity were observed.

Conclusions

Phospho-flow analysis identified phosphorylation-activation of specific signaling effectors in the PB from patients with ERA. Notably, phosphorylation of these signaling effectors did not distinguish ERA from late RA, suggesting that the activation status of discrete cell populations is already established early in disease. However, when the ratio of MFI values for p-AKT and p-p38 is >1.5, there is a high likelihood of having a diagnosis of RA. Our results suggest that longitudinal sampling of patients undergoing therapy may result in phospho-signatures that are predictive of drug responsiveness.     

Early Initiation of Smoking and Alcohol Drinking as a Predictor of Lower Forearm Bone Mineral Density in Late Adolescence: A Cohort Study in Girls

Background

Adolescence is a critical stage for bone accrual. It is also decisive for the establishment of behaviors such as smoking and alcohol drinking.

Objective

To quantify the short- and long-term associations between smoking and drinking initiation and bone mineral density in adolescent girls.

Methods

We used prospective data from 731 girls identified in public and private schools in Porto, Portugal. Evaluations were conducted when participants were 13 and 17 years old. Bone mineral density (BMD) was measured at the forearm by dual-energy X-ray absorptiometry and weight, height and fat-free mass were measured. Pubertal development status was estimated using menarche age. Self-administered questionnaires were used to collect data on smoking and alcohol drinking, physical exercise and calcium and vitamin D intakes. BMD in early and late adolescence was analyzed as a continuous or dichotomous (Z-score cutoff: −1.0) variable. Associations were calculated using linear or logistic regression.

Results

Over one quarter of these girls had tried smoking by 13, while 59% had drunk alcoholic beverages and 20% had experienced both behaviors by that age. Lower mean BMD at 17 years of age was observed in girls who had ever smoked by 13, as well as in those who reported drinking at that age. There were no significant cross-sectional associations between experience and frequency of smoking or drinking and BMD at 13 years of age. However, we observed significant associations between BMD z-score<−1 in late adolescence and having ever smoked by 13, after adjustment for menarche age and sports practice, (OR = 1.92; 95% CI: 1.21, 3.05) and with ever smoking and drinking in the same period (OR = 2.33; 95% CI: 1.36, 4.00).

Conclusion

Our study adds prospective evidence to the role of early initiation of smoking and alcohol drinking as relevant markers of lower bone mineral density in late adolescence.     

依那西普联合甲氨蝶呤治疗类风湿关节炎疗效分析

目的:探讨依那西普联合甲氨蝶呤治疗类风湿关节炎的疗效。方法:选取2011年至2013年风湿免疫科的60例类风湿关节炎患者,分为对照组和治疗组,其中对照组15例,治疗组45例,两组患者都应用甲氨蝶呤治疗,治疗组患者联合使用依那西普治疗,总疗程12周。比较两组患者治疗前后的临床及实验室指标。采用美国风湿病学会的核心标准作为疗效评定标准。结果:治疗组患者肿瘤坏死因子(tumor necrosis factor,TNF)和白细胞介素(interleukin,IL-1)下降明显,与对照组患者相比差异均有统计学意义(P0.05);治疗后两组患者超敏C反应蛋白(hs-CRP)均较治疗前明显降低,差异均有统计学意义(P0.05);治疗组患者关节疼痛、关节肿胀和晨僵情况较对照组均有显著的改善(P0.05);治疗组患者的休息痛、患者评分以及HAQ评分均显著优于对照组(P0.05);治疗组患者ACR20和ACR70缓解的比例均高于对照组,且治疗组患者达ACR50缓解的比例显著高于对照组(P0.05)。结论:依那西普联合甲氨蝶呤治疗类风湿关节炎的疗效优于单纯的甲氨蝶呤治疗。     

An Osteoprotegerin Gene Polymorphism Is Associated with an Increased Risk of Hip Fracture in Japanese Patients with Rheumatoid Arthritis: Results from the IORRA Observational Cohort Study

Introduction

Patients with rheumatoid arthritis (RA) have a higher prevalence of osteoporosis and hip fracture than healthy individuals. Multiple genetic loci for osteoporotic fracture were identified in recent genome-wide association studies. The purpose of this study was to identify genetic variants associated with the occurrence of hip fracture in Japanese patients with RA.

Methods

DNA samples from 2,282 Japanese patients with RA were obtained from the DNA collection of the Institute of Rheumatology Rheumatoid Arthritis cohort (IORRA) study. Six single nucleotide polymorphisms (SNPs) that have been reported to be associated with fractures in recent studies were selected and genotyped. Forty hip fractures were identified with a maximum follow-up of 10 years. The genetic risk for hip fracture was examined using a multivariate Cox proportional hazards regression model.

Results

The risk analyses revealed that patients who are homozygous for the major allele of SNP rs6993813, in the OPG locus, have a higher risk for hip fracture (hazard ratio [95% CI]  = 2.53 [1.29–4.95], P  = 0.0067). No association was found for the other SNPs.

Conclusions

Our results indicate that an OPG allele is associated with increased risk for hip fracture in Japanese patients with RA.     

Economic Impact of Maternal Death on Households in Rural China: A Prospective Cohort Study

Objective

To assess the economic impact of maternal death on rural Chinese households during the year after maternal death.

Methods

A prospective cohort study matched 183 households who had suffered a maternal death to 346 households that experienced childbirth without maternal death in rural areas of three provinces in China. Surveys were conducted at baseline (1–3 months after maternal death or childbirth) and one year after baseline using the quantitative questionnaire. We investigated household income, expenditure, accumulated debts, and self-reported household economic status. Difference-in-Difference (DID), linear regression, and logistic regression analyses were used to compare the economic status between households with and without maternal death.

Findings

The households with maternal death had a higher risk of self-reported “household economy became worse” during the follow-up period (adjusted OR = 6.04, p<0.001). During the follow-up period, at the household level, DID estimator of income and expenditure showed that households with maternal death had a significant relative reduction of US$ 869 and US$ 650, compared to those households that experienced childbirth with no adverse event (p<0.001). Converted to proportions of change, an average of 32.0% reduction of annual income and 24.9% reduction of annual expenditure were observed in households with a maternal death. The mean increase of accumulated debts in households with a maternal death was 3.2 times as high as that in households without maternal death (p = 0.024). Expenditure pattern of households with maternal death changed, with lower consumption on food (p = 0.037), clothes and commodity (p = 0.003), traffic and communication (p = 0.022) and higher consumption on cigarette or alcohol (p = 0.014).

Conclusion

Compared with childbirth, maternal death had adverse impact on household economy, including higher risk of self-reported “household economy became worse”, decreased income and expenditure, increased debts and changed expenditure pattern.     

Expression of the Inherently Autoreactive Idiotope 9G4 on Autoantibodies to Citrullinated Peptides and on Rheumatoid Factors in Patients with Early and Established Rheumatoid Arthritis

Background

The pre-symptomatic stage of Rheumatoid arthritis (RA) is associated with pro-inflammatory cytokines and autoantibodies. High levels and epitope spread by Rheumatoid factors (RhF) and autoantibodies to citrullinated proteins signify progression towards disease expression. In established RA, the persistence of high autoantibody levels reflects production by both long-lived plasma cells and short-lived plasmablasts. Neither the relative contributions to pathogenesis by autoantibodies from either source, nor the factors responsible for deciding the fate of autoantigen specific ‘parent’ B-cells, is understood. Phenotypic markers identifying subsets of autoreactive B-cells are therefore of interest in understanding the origin and perpetuation of the autoimmune response in RA. One such phenotypic marker is the rat monoclonal antibody, 9G4, which recognises an idiotope on immunoglobuins derived from the inherently autoreactive VH-gene, VH4-34. We therefore investigated whether the 9G4 idiotope was expressed on autoantibodies in patients with RA.

Methodology/Principal Findings

Sera from 19 patients with established RA and those with <1year history of untreated polyarthritis either resolving into RA (n = 42) or non-RA diagnosis (n = 31) were included. Autoantibodies to cyclic citrullinated peptides (CCP), RhF and co-expression of the 9G4 idiotope were measured by ELISA. 9G4 recognised a population of anti-CCP antibodies in the majority of sera from patients with established disease and also in samples from patients with early disaese. 9G4+RhF levels were generally lower and not associated with positivity for, or levels of 9G4+CCP.

Conclusions/Significance

The persistence of 9G4+ immunoglobulins, of any isotype, in serum is rare. We describe here the novel finding of 9G4 expression on anti-CCP antibodies in patients from the earliest symptoms of RA through to established disease. Our results suggest that 9G4 expression on anti-CCP autoantibodies was not due to polyclonal expansion of VH4-34-encoded immunoglobulins. These studies may therefore provide a new focus for investigation into the evolution of the autoimmune response in RA patients.     

Effect of Dialysis Initiation Timing on Clinical Outcomes: A Propensity-Matched Analysis of a Prospective Cohort Study in Korea

Background

Controversy persists regarding the appropriate initiation timing of renal replacement therapy for patients with end-stage renal disease. We evaluated the effect of dialysis initiation timing on clinical outcomes. Initiation times were classified according to glomerular filtration rate (GFR).

Methods

We enrolled a total of 1691 adult patients who started dialysis between August 2008 and March 2013 in a multi-center, prospective cohort study at the Clinical Research Center for End Stage Renal Disease in the Republic of Korea. The patients were classified into the early-start group or the late-start group according to the mean estimated GFR value, which was 7.37 ml/min/1.73 m². The primary outcome was patient survival, and the secondary outcomes were hospitalization, cardiovascular events, vascular access complications, change of dialysis modality, and peritonitis. The two groups were compared before and after matching with propensity scores.

Results

Before propensity score matching, the early-start group had a poor survival rate (P<0.001). Hospitalization, cardiovascular events, vascular access complications, changes in dialysis modality, and peritonitis were not different between the groups. A total of 854 patients (427 in each group) were selected by propensity score matching. After matching, neither patient survival nor any of the other outcomes differed between groups.

Conclusions

There was no clinical benefit after adjustment by propensity scores comparing early versus late initiation of dialysis.     

Prices,Costs, and Affordability of New Medicines for Hepatitis C in 30 Countries: An Economic Analysis

IntroductionNew hepatitis C virus (HCV) medicines have markedly improved treatment efficacy and regimen tolerability. However, their high prices have limited access, prompting wide debate about fair and affordable prices. This study systematically compared the price and affordability of sofosbuvir and ledipasvir/sofosbuvir across 30 countries to assess affordability to health systems and patients.ConclusionsCurrent prices of these medicines are variable and unaffordable globally. These prices threaten the sustainability of health systems in many countries and prevent large-scale provision of treatment. Stakeholders should implement a fairer pricing framework to deliver lower prices that take account of affordability. Without lower prices, countries are unlikely to be able to increase investment to minimise the burden of hepatitis C.     

Lunar Effect on Thoroughbred Mare Fertility: An Analysis of 14 Years of Data, 1986-1999

It became possible to access the yearly studbooks of a major UK Thoroughbred studfarm. By comparing these with subsequent published records of horse-breeding, one could compare the coverings between mares and stallions with the outcome as to whether or not a registered conception occurred. The coverings went on seven days a week with no interruption, over the breeding months of early spring and summer, and so offered an opportunity to test hypotheses concerning the lunar phase cycle. Since the studbooks began, vets have been able to detect the onset of estrus every three weeks, so that the covering dates give a fairly unerring record of mare estrus. Two logically distinct parameters were here tested: the extent to which the onset of estrus was related to the lunar month, and then whether the proportion of successful coverings varied with the lunar month.

A total of 14 successive years of studbook data was recorded and tested in this manner, partly to average out irregularities in lunar angular speed resulting from the apogee-perigee cycle (linked to the 9-year apse cycle) and partly to be able to investigate whether the 18.6-year nutation cycle would affect the way in which the lunar-month cycle worked. This notion came from geomagnetic surveys, which have showed a sizeable modulation of the geomagnetic field with the synodic cycle, with the modulation of this by the lunar-node cycle. The notion of an influence of the synodic cycle being modulated by the 18-year nutation cycle is supported by the present enquiry. One could choose to view this as, effectively, a 9-year cycle, insofar as no distinction was here made between the two lunar nodes. The method employed five successive lunar-days (one-sixth of the lunar month) to investigate the peaks and troughs of the synodic cycle.     

Hypoglycemia and Medical Expenses in Patients with Type 2 Diabetes Mellitus: An Analysis Based on the Korea National Diabetes Program Cohort

Background and Aims

Hypoglycemia is one of the most important adverse events in individuals with type 2 diabetes mellitus (T2DM). However, hypoglycemia-related events are usually overlooked and have been documented less in clinical practice.

Materials and Methods

We evaluated the incidence, clinical characteristics, and medical expenses of hypoglycemia related events in T2DM patients based on the Korea National Diabetes Program (KNDP), which is the largest multi-center, prospective cohort in Korea (n = 4,350). For accurate outcomes, the KNDP data were merged with claims data from the Health Insurance Review and Assessment Service (HIRA) of Korea.

Results

During a median follow-up period of 3.23 years (95% CI: 3.14, 3.19), 88 subjects (2.02%) were newly diagnosed with hypoglycemia, and the incidence of hypoglycemia was 6.44 cases per 1,000 person-years (PY). Individuals with hypoglycemia were significantly older (59.7±10.7 vs. 53.3±10.4 years, p < 0.001), had more hospital visits (121.94±126.88 days/PY, p < 0.001), had a longer hospital stays (16.13±29.21 days/PY, p < 0.001), and incurred greater medical costs ($2,447.56±4,056.38 vs. $1,336.37±3,403.39 /PY, p < 0.001) than subjects without hypoglycemia.

Conclusion

Hypoglycemia-related events were infrequently identified among the medical records of T2DM subjects. However, they were associated significantly with poor clinical outcomes, and thus, hypoglycemia could have a substantial burden on the Korean national healthcare system.     

Impact of the Time-Weighted Average Glucose Concentration and Diabetes on In-Hospital Mortality in Critically Ill Patients Older Than 75 Years: A Retrospective Cohort Study

ObjectiveTo evaluate the effects of diabetes and hyperglycemia on in-hospital mortality in critically ill patients older than 75 years.MethodsThis was a single-center retrospective cohort study of patients older than 75 years in the first intensive care unit stay. The patients were divided into the following 4 groups: time-weighted average glucose (TWAG) <140 mg/dL without diabetes (group 1), TWAG ≥140 mg/dL without diabetes (group 2), TWAG <180 mg/dL with diabetes (group 3), and TWAG ≥180 mg/dL with diabetes (group 4). Clinical and laboratory data were analyzed.ResultsA total of 6760 patients over 75 years of age were included, including 2089 patients previously diagnosed with diabetes. The patients in group 2 had the highest in-hospital mortality (27.4%). In the fully adjusted regression model, the risk of in-hospital mortality increased by 76% (odds ratio = 1.76, 95% CI: 1.49-2.08) in group 2 as compared with group 1. Those from groups 3 and 4 exhibited risks equivalent to the risks of those in group 1; similar results were observed in the subgroup analysis. A J-shaped curve relationship and threshold effect were observed in patients without diabetes. For those with diabetes, a flatter curve pattern with a small slope was observed.ConclusionStress hyperglycemia was more detrimental to short-term prognosis than diabetes status in these patients. Looser glucose control may be suitable for patients older than 75 years with diabetes but unnecessary for those without diabetes. Patients with diabetes may be more resistant to the detrimental effects of glucose variations.     

Impact of Maternal Obesity on Inhaled Corticosteroid Use in Childhood: A Registry Based Analysis of First Born Children and a Sibling Pair Analysis

Background

It has been proposed that maternal obesity during pregnancy may increase the risk that the child develops allergic disease and asthma, although the mechanisms underpinning this relationship are currently unclear. We sought to assess if this association may be due to confounding by genetic or environmental risk factors that are common to maternal obesity and childhood asthma, using a sibling pair analysis.

Methods

The study population comprised a Swedish national cohort of term children born between 1992 and 2008 to native Swedish parents. Maternal body mass index (BMI) was measured at 8–10 weeks gestation. Unconditional logistic regression models were used to determine if maternal obesity was associated with increased risk of inhaled corticosteroid (ICS) in 431,718 first-born children, while adjusting for potential confounders. An age-matched discordant sib-pair analysis was performed, taking into account shared genetic and environmental risk factors.

Results

Maternal over-weight and obesity were associated with increased risk that the child would require ICS (for BMI≥35 kg/m², aOR = 1.30, 95%CI = 1.10–1.52 compared with normal weight mothers) in children aged 6–12 years. Similar effects were seen in younger children, but in children aged 13–16 years, maternal obesity (BMI≥30) was related to increased risk of ICS use in girls (aOR = 1.28, 95%CI = 1.07–1.53) but not boys (OR = 1.05, 95%CI = 0.87–1.26). The sib-pair analysis, which included 2,034 sib-pairs older than six years who were discordant for both ICS use and maternal BMI category, failed to find any evidence that increasing maternal weight was related to increased risk of ICS use.

Conclusion

Maternal obesity is associated with increased risk of childhood ICS use up to approximately 12 years of age, but only in girls after this age. These effects could not be confirmed in a sib pair analysis, suggesting either limited statistical power, or the effects of maternal BMI may be due to shared genetic or environmental risk factors.